1. Field of the Invention
The invention relates to the lighting of aviation obstructions (e.g., towers and other structures that may pose a danger to aircraft), and to an aviation obstruction lighting system and to an aviation obstruction equipped with such a lighting system.
2. Description of Related Art
Legal requirements exist for the lighting of aviation obstructions, which for example in Germany are described in the “General Administrative Regulation on the Marking of Aviation Obstructions.” In describing the detailed technical stipulations concerning the design of such lighting systems, this administrative regulation refers to the US ICAO standard, Annex 14: “Aerodomes.” Similar requirements are promulgated in the United States by the Federal Aviation Administration.
According to the German standard, outside of airports three types of lighting elements are usually used as obstruction lighting by day and by night, which are listed in the aforementioned ICAO standard with the following designations:
“Low Intensity, Type B” are lamps producing continuous red light of low intensity for obstruction lighting at night and in twilight, preferably for emphasizing the outer contours of obstructions;
“Medium Intensity, Type A” describes a white flashing light, which must emit a luminous intensity of >20,000 cd in daylight and >2,000 cd at night and, for example in Germany, is to be installed in individual cases on aviation obstructions with a height of 150 m and above. The color temperature of the white light must be between 4,000 K and 8,000 K;
“Medium Intensity, Type B” describes a red flashing light which, in individual cases, is used at night with a luminous intensity>2,000 cd as a hazard warning signal on aviation obstructions with a height of over 150 m.
In some embodiments, the lamps of the “Medium Intensity” types A and B are combined in a single lighting fixture.
Incandescent lamps (only for red light), xenon lamps, and increasingly LEDs are usually used as light sources. These lamps are supplied with energy via electrical supply cables laid on the aviation obstruction. In the case of LEDs, as well as the usual local mains voltage, low-voltage cables are also used which, if repairs or maintenance work are necessary, avoid the hazard of an electric shock for the persons carrying out the maintenance/repairs.
Autonomous voltage supply concepts involving solar modules and storage batteries are also increasingly used, at least reducing the hazards arising from high voltages and the costs of laying the connecting cables.
Due in particular to the regular lightning strikes on such aviation obstructions, it is frequently necessary to repair defective lamps, electrical circuits and supply cables at very great heights. The work involved considerably increases the maintenance costs of the aviation obstructions and presents not inconsiderable risks to the repair personnel working at great heights.